Improvement in steam-gage cases



2Sheets--Sheet1. H. BELFIELD.

-lmprovement in Steam-Gauge Cases.

N0. 131,651. Patented Sep.24,1872.

2 Sheets--8heet 2.

. H. BELHELD.

1 Improvement in Steam-Gauge Cases. I

No. 131,651,,' Patented Sep. 24, i872.

UNITED STATES HENRY BELFIELD, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN STEAM -GAGE CASES.

Specification forming part of Letters Patent No. 131,651, datedSeptember 24, 1872.

To all whom it may concern:

Be it known that I, HENRY BELFIELD, of Philadelphia, in the county ofPhiladelphia and in the State of Pennsylvania, have invented certain newand useful Improvements in Steam-Gages; and do hereby declare that thefollowing is a full, clear, and exact description thereof, referencesbeing had to the accompanying drawing making a part of thisspecification, in which Figure 1 is a plan view of the front side of thecasing with the dial and recording mechanism removed; Fig. 2 is a likeview of the rear side of said casing; Fig. 3 is a central crossseotionof the same on lines was of Figs. 1 and 2; Fig. 4 is an enlarged centralsection of the corrugated diaphragms; Fig. 5 is a plan view of the innerside of the back plate; and Fig. 6 i}; a cgntral section of the same onthe line 2 z of Letters of like name and kind refer to like parts ineach of the figures.

My invention is an improvement in a class of steam-gages in which thepressure of steam is transmitted to the recording mechanism through orby means of one or more corrugated metallic diaphragms; and it consistsin the combination of the open recessed back of the casing, the recessedback plate, and the corrugated diaphragm, substantially as and for thepurpose hereinafter specified.

In the annexed drawing, A represents the exterior wall of the casing,made open at its front side and provided at its rear side with a flange,B, which extends radially outward and affords means whereby the devicemay be secured to or upon a suitable supporting surface. The back 0 ofthe casing is set sufficiently forward from the rear edge of the same toform a recess, D, while through the center of said back is provided acircular opening, 0, which corresponds in diameter with the corrugatedportion of the metallic diaphragms E. Upon the rear side of said back,and surrounding said opening, is provided a raised concentric bearing,0, upon which the plane edges 0 of said diaphragms rest when the sameare in position. Fitted to or within the recess D is a circular disk orplate, F, which has a diameter equal to or about two-thirds the diameterof said recess, and is provided with a raised concentric bearing, f,that corresponds in dimensions to or with the bearing 0. The plate Fwithin the beariu g f is sunk somewhat below the outer portion of saidplate so as to form a recess, G, which communicates laterally, by meansof a duct, 9, with a hollow boss, H, that is attached to the lower edgeand inner side of said plate. As the boss H is entirely within the lineof the rear side of the plate F, provision for its reception is made byforming a corresponding recess, H, within the contiguous portion of theback 0, while an opening, h, passing outward through the easin g A, andcoinciding with the opening h, which passes through said boss, permitsaccess to be had thereto when the said plate is in position. A series ofbolts, I, passing through the back 0 into the plate F, outside of thebearing f, connect the latter to or with the casing and insure theirrelative positions. The casing is now ready for the diaphragms E, whichare placed over the opening 0, with their plane edges e between thebearings c andf, in which position they are firmly secured by the inwardpressure of the bolts I, and form a steam-chamber of the recess G,except where outward communication is had through the passage 9 andopenin g h, which openings, by means of a pipe attached to the boss Hand connected with the boiler, afi'ord ready access for steam" into saidchamber. It will seen that the only points at which steam could escapefrom the chamber G are between the diaphragm E and bearing f, and at thejoint between the steam-pipe and the boss H, and as both of said jointsare entirely outside of the main portion of the casing, and separatedtherefrom by the joint between the diaphragm and bearing 0, it isentirely impracticable that any stcam or water should pass into saidcasing to injure the operating mechanism or obscure the covering glass,as is common in gages of this class.

While possessing the advantages enumerated, the usual circular form ofthe casing is preserved and all separate and independent boxes orcasings for the diaphragms rendered unnecessary.

Much difficulty is usually experienced in combining two or morediaphragms so as to cause them to act with uniformity upon the recordingmechanism and to permit the dial to be equally spaced, as from theirpeculiar shape and the manner of constructing them perfect uniformitycannot be secured and their contiguous surfaces made to bear with equalpressure at all points. To remedy this defect, I place between thebearing-flanges e, of the diaphragms, a concentric ring of sheet metal,K, so as to separate the corrugated portions of said diaphragms andallow them to act with freedom, and between their centers I place smallmetal plates L, which have a sufficient thickness to produce a slightoutward strain upon said parts and to cause them to remain 1 in contact.As thus arranged, it will be seen that outward pressure upon the reardiaphragm will be instantly communicated through its central portion tothose in front, and through the latter to the operating-lever, and thatas said parts are always in contact at their centers while the remainderof each is free to act independently of the others, the outward motionof the combined dlaphragms must correspond in degree with the pressureof the steam. In some instances it will be found that the natural set ofthe diaphragms will afford just the required clearance of theircorrugated portions or the necessary bearing of their centers, in whichevent the ring K or disk L may be omitted, but by their judiciousemployment the tension of the combined diaphragms can be made as uniformand regular as though but one of the latter was used.

Having thus fully set forth the nature and merits of my invention, whatI claim as new 1s-- The casing A, provided with the open recessed back0, the corrugated diaphragm E, and the back plate F, provided with therecess G and hollow boss H, when said parts are constructed andcombined, substantially as and for the purpose specified.

In testimony that I claim the foregoing I have hereunto set my hand this24th day of February, 1872.

HENRY BELFIELD. Witnesses:

W. G. BUCHANAN, THos. S. STOUT.

